Improved process for making steel direct from the ore



UNITED STATES PATENT OFFICE;

GEORGE HAND SMITH, OF ROCHESTER, NEW YORK.

I MPROVED PROCESS FOR MAKING STEEL DIRECT FROM TH BORE:

Specification forming part of Letters Patent No. 111,338, dated July 18,1854. I i i A To all whom 'it may concern:

Be it known that I, GEORGE HAND SMITH, M. 1)., of Rochester, New York, have invented a new, Process for the lvlanuf'acture of Steel Direct from the Ore, of which the following is a full, clear, and exact description.

My invention relates to a process for deoxidizing and carbonizing iron ores and producing therefrom either spring or cast steel; and my said invention consists in treating the ore in a comminuted state and mixed with charcoal or other carbonaceous matter, and with or without other flux, depending on the nature of the ore, in a close cementing oven, retort, or other suitable close vessel, at a high degree of heat-say about a white heat-and after it has been deoxidized, if an oxide, and the carbonic acid expelled, if a carbonate, and then carbonized, separating the metallic particles of steel from the remaining impurities, and then, for making spring-steel, welding the particles in a reheating furnaceand rolling or hammering it into bars; and for cast-steel, melting the particles of carbonized metal in crucibles, in the usualmanner of making cast from blistered steel.

The mode of procedure which I have practiced with success is as follows, viz: By any of the known and suitable means the ore is crushed or ground tolumps of about the size of forty to the inch (more or less) and then, as far as possible, mechanically separated from theearthy and other impurities, the object being twofold. First, the better to effect the separation of the earthy impurities; and, second, to present the metallic particles in such a state that they will be readily and uniformly charged with carbon. And thus' prepared it is charged in a cementing-oven, such as is used for making blistereil steel, or in a retort or other suitable vessel with pounded or ground charcoal or other car-' bonaceous matter.

The charge should be in alternate layers of has reached what is termed a,wl1ite heat,it is.

gree of temper (carbonization) required. temperature required and expressed by white heat is just short of fluidity, as the object is I to effect the change without melting the particles of iron, which would thereby be overcharged. For a large oven containing a charge of about twenty tons of ore the heat should be applied about six days, the greater portion of which time will be consumed in heating the oven and bringing up the charge to the required temperature.

The mode of testing the degree of carbonization is by the color of the surface of the ore. When properly charged with carbon the ore as sumes (in cooling) a blue and yellow color and combinations of these colors, and then passes to a brown, and finally, when overcharged, to a gray color. By taking out portions otthc ore the operator can tell by the colors when the required temper is reached, and then the tire is to be discontinued and the charge permitted to cool down in the oven. During the converting process the particles of ore become united by the earthy impurities and the flux, if any be used in addition to the carbon, and each layer forms a sheet. When cooled and taken out of the oven the mass is to be rebroken or crushed, and the metallic particles separated from the impurities by magnets, or' by blowing or other suitable means, and it it is to he made into cast-steel it must be melted in crucibles and cast into ingots precisely as in the well-known process of making cast-steel from blistered steel; but if to be converted in to springsteel, the articles are to be worked in a furnace such as is used for balling scrap-iron, and there heated to a welding heat, but not so long as to burn out the carbon, and balled and either rolled or hammered into bars, as may be required.

When, by the neglect of the operator or from any other cause, it is found that the metallic particles have been overcharged with carbon, the mass is to be treated in a reheating-fun nace such as is used for balling scrap-iron, and there puddled to expel the surplus of carbon, and then balled and hammered and rolled into spring-steel, or broken up and treated in the crucible to be made into cast-steel.

It is not deemed necessary to describe the various kinds of flux which may be used in addition to the carbon, as'the necessity for and the kindto be used will depend upon the coir stituents of the ore and the properties other than the temperature required to be imparted to the steel, and as these are all matters wellknown to iron-masters and foreign to my inrention, which relates simply to the process of converting iron ore directly into steel, it is deemed unnecessary to specify the kinds oi flux to be used other than carbon.

This process is as equally applicable to the ores known as carbonatesas to the oxides, for in the carbonates the carbon is not mixed with the iroinalone, as in the-case of steel, but it is united with the iron in the form of carbonic acid, which must be expelled before the union is formed between the iron and carbon without oxygen to produce good steel.

What I claim as my invention, and desire to secure by Letters Patent, is-

The'pi'oeess of eo'nvertin g theiron ores known as the oxides and carbonates directly into steel by subjecting the ore in the comminuted state with carbon, and with or without other flux, in a close oven, retort, or other vessel to a high degree of heat-say about the temperature of what is known as white heatand then separating the metallic particles from the impurities, and either melting them in crucibles to produce cast-steel or welding and balling them in a reheating-furnace and subjecting the mass to pressure by rolling I or hammering to produce spring-steel, all substantially as specified.

" GEORGE HAND SMITH.

Witnesses:

WM. H. BISHOP, CHAs. W. BAMBURGH. 

